Newbie Torque Wrench Question

[Memory Leak]

Hello,

I have a torque wrench which I bought from tire rack initially to change my tires (http://www.tirerack.com/accessories/detail.jsp?make=Tire+Rack&partnum=TW605&ID=75). It works perfectly fine as is, however, now I need to change my oil and I want to use this wrench to loosen the drain plugs under the car. These plugs require 18NM to tighten which corresponds to 13 lb/ft torque.

The wrench however only has 20 as the minimum number. The tire rack's website says it's "up to 150 lb/ft" which implies 0 to 150. In addition, I can use the screw like dial to go backwards from 20 to 10 and 0 (even though there is no 10 in the main lever). Is this okay or does my wrench not support torque values below 20?

Thanks.

 

[Fast Orange]

Welcome to GJ-
Torque Wrench 101- Torque wrenches are not usually used for disassembly or drain plug removal-the proper tool is either a wrench or a socket on a ratchet.Using your TW for this type of work only promotes more wear and tear on a relatively expensive tool and serves no useful purpose. Although not really necessary,you could use the TW for final tightening of the drain plugs-most people just tighten them to "snug" and let it go at that.
All torque wrenches have a minimum torque value-they will be very inaccurate if used below this range.Highest accuracy is usually around the midpoint of the range. Should you need to torque fasteners lower than the range of your TW,you will need to get a TW with the proper range.

 

[toolaholic]

Do not use it below 20. It will not be accurate and may not be good for torque wrench. Use a ratchet,wrench or breaker bar to break fasteners loose. The only time I use reverse in a torque wrench is if I tightened to tight w/ ratchet and torque wrench clicks right away when using for final torque; I will reverse torque wrench to loosen fastener then put in forward and tighten til click.

 

[Scott H in Wheaton]

Yep, no need for a torque wrench for drain plugs! You could ruin the plugs and/or the wrench!

Keep this handy reference in mind....things that go around and around like wheels need to be 'gorilla tight'

Drain plugs only need to be 'monkey tight'

 

[Memory Leak]

Thanks for the responses.

I'm not sure I understand what you are saying though in terms of loosening them. How does it matter whether I use a torque wrench or a ratchet to loosen the plugs? I was actually more worried about tightening them.

The car in question is a BMW M3 otherwise I wouldn't care much about tightening the plugs and do it by hand. With a car like this you don't want to take any chances especially when the manual says 18NM which is around 13 lb/ft.

My question is also more about the specific torque wrench I bought (linked in my OP). In their page tire rack states "up to 150 lb/ft". That in my book implies 0 to 150. The wrench however has 20 as the minimum number BUT, I can always use the lower dial to go backwards to 13. They are either falsely advertising or this is a bad wrench. I paid $40 for it, not sure what to do now

 

[JCQuick]

ALL Torque wrenchs have a minimium setting. I use a small 3/8" torque wrench for most stuff under 50lbs and a 1/2" for the larger. I work witha lot of BMW mechanics I can asure you they are not torquing drain plugs

 

[darwyn]

For the minimum setting, try reading this:
http://www.garagejournal.com/forum/showthread.php?t=103857

Not sure I would get too fired up on false advertising for a $40 torque wrench ...

 

[Memory Leak]

For the minimum setting, try reading this:
http://www.garagejournal.com/forum/showthread.php?t=103857

Not sure I would get too fired up on false advertising for a $40 torque wrench ...

Got it, thank you.

Since I'm a newbie, how much does hand tightening something correspond to in terms of lb/ft?

Also, what is a "decent" torque wrench that I can use for something as little as 10-15 lb/ft or as much as 90 lb/ft?

 

[darwyn]

Put a nut in a vice, and tighten a bolt in it with your ratchet. Put your torque wrench on its minimum setting and try to tighten the nut. If your torque wrench clicks, keep bumping up the torque until it doesn't. That will give you an idea of how much torque you are using.
Play around until with tightening your bolt until you get a feel for it. For me, my 3/8 drive ratchet with a sharp tug will put me at about 20 lb ft. Anything more than 40 lb ft and I would need a bigger ratchet.
If you are really new to wrenching, I would also suggest using a small bolt in a vice and stripping it. Knowing how a bolt feels when it strips is best learned on something cheap.

oh yeah, in answer to your question, a few?

 

[robin1731]

Actually a torque wrench that starts at 20lf-lbs isn't even real accurate till about 30ft-lbs or so. Any torque wrench isn't accurate until a bit past it's minimum setting. It's a percentage from the minimum. I don't remember what it is but any good truck tool guy could tell you.

 

[AMCguy]

If your BMW oil pan is aluminum, it's a good idea to use a torque wrench to tighten the drain plug. Quite simply it puts a value on the torque you are applying. You may not be confident that you'll have the same accuracy if you don't have a lot of wrenching experience.

I recommend you by an in/lb torque wrench in addition to the one you just bought. Look for one in the 0-300 in/lb range. 13 ft/lbs x 12'' is 156 in/lbs. that would be right in the middle of the scale on that wrench.

You can't use your ft/lb torque wrench for what you are trying to do. It would be like using a bathroom scale to weigh a letter.

 

[Mumbly00]

Got it, thank you.

Since I'm a newbie, how much does hand tightening something correspond to in terms of lb/ft?

Also, what is a "decent" torque wrench that I can use for something as little as 10-15 lb/ft or as much as 90 lb/ft?

For routine maintenance I rarely break out my torque wrenches, usually I only time I do is if there is there is a wheel involved. Everyone perceives strength differently so something for one person isn't going to be the same. For someone starting out I like the idea posted above with the vise and stripping bolts. As far as the question about the drain, I usually screw the bolt back in till it stops when minimal pressure is applied, then I give it a light tap.

For your first couple times doing it, leave the car up in the air after filling with oil to make sure no oil is leaking. If nothing comes out in 10 minutes it's doubtful you'll dump 5 quarts and destroy your motor.

The more you do it the easier it gets, I can change oil in under a 12oz beer (doesn't mean I do it)

 

[Denwad]

I have a 98 M3 and I over tightened my drain plug once

the good thing is the bolt is a hollow bolt that will just break if you over torque it, it will not strip the threads in the pan

that being said, just run the plug down by hand ( with a new copper or aluminum crush washer, do not reuse the old one ) and give it a quarter turn ( like a spark plug )

 

[the.wong.kid]

It works perfectly fine as is, however, now I need to change my oil and I want to use this wrench to loosen the drain plugs under the car.

just an fyi, you should not use a torque wrench to loosen anything, i know alot of torque wrench has a 'off' switch for the loosen direction. but using a torque wrench to loosen anything actually damages the internals of the tool and throws if off calibration

 

[dragonballz]

Even though some torque wrenches has a reverse, don't use it to loosen. The "snap" when youre breaking a fastener loose can damage the wrench. It is made to torque left hand threaded fasteners


Torque your oil drain plug. It may save you time and money in the long run. Quick and easy insurance. All it takes is a simple mistake to ruin your threads. It's even easier in aluminum. Especially since youre a noobie.

 

[nicksnothereman]

Hello,

I have a torque wrench which I bought from tire rack initially to change my tires (http://www.tirerack.com/accessories/detail.jsp?make=Tire+Rack&partnum=TW605&ID=75). It works perfectly fine as is, however, now I need to change my oil and I want to use this wrench to loosen the drain plugs under the car. These plugs require 18NM to tighten which corresponds to 13 lb/ft torque.

The wrench however only has 20 as the minimum number. The tire rack's website says it's "up to 150 lb/ft" which implies 0 to 150. In addition, I can use the screw like dial to go backwards from 20 to 10 and 0 (even though there is no 10 in the main lever). Is this okay or does my wrench not support torque values below 20?

Thanks.

A)Don't use a torque wrench to loosen anything. (not kidding)
B)Don't use a torque wrench on the oil drain plug. (you can but hand tighten is good enough). Don't overtorque that bolt to the degree you want to fit it in with the scale of the torque wrench. Lower end and higher end values will be wildly inaccurate anyway.
C)You don't really need a torque wrench to tighten lugs. If it loses calibration you can potentially snap lugs. Best way to do it if go hand tight with a 4 way then incrementally increase the torque values on your wrench and let it click from say 50-80 (with 80 being your desired value) to ensure you're getting the correct value.

 

[Memory Leak]

Hi again,

Thanks a lot for very helpful responses. I had no idea about not using a torque wrench to loosening lug nuts. I did this several times I guess I may have thrown the calibration off. How can I check to see if the calibration is not off?

I am going to get a Tekton inch/lb torque wrench as well. Looking to get this one : http://www.amazon.com/dp/B00C5ZL2EG/?tag=atomicindus08-20.

That being said, all of my hex sockets are 3/8. Is it going to be a problem to get an adapter? Furthermore, if I need an extension for the wrench, should the extension be in the wrench's size or the hex socket's size? i.e. the wrench is 1/4 inch and the hex socket is 3/8. I will get an adapter to go from 1/4 to 3/8. So should the extension be 1/4 or 3/8? Does having both an adapter and an extension impact the torque wrench in a bad way? I couldn't find a good inch/lb wrench that has a low range. I am going to need 10NM and 18NM. The lowest I could find was 20-200. Also, if there is a better brand you can recommend, feel free to do so.

I don't want to go cheap on this stuff. As for those of you saying hang tighten the drain plugs, I don't want to really argue but if the manufacturer said 18NM specifically, why go against it? Especially in a car like this. You never know what might happen in the future in a warranty claim I wouldn't want to be blamed for not following instructions.

Thanks again for your help.

 

[doug.j]

That model seems a little weak. It is listed in in/lb not ft/lbs. i'd go for a 3/8 drive.

 

[Memory Leak]

That model seems a little weak. It is listed in in/lb not ft/lbs. i'd go for a 3/8 drive.

I don't see many options in 3/8 unfortunately. The one tekton has in 3/8 got a lot of bad reviews.

Is there another brand you guys recommend?

I don't need one for ft/lbs, I need one in in/lb. I need this torque wrench for 10, 18, and 28NM. That's not a lot of torque.

 

[toolaholic]

This is what I use: http://www.amazon.com/dp/B002Z34UDI/?tag=atomicindus08-20 It goes down to 5 lbft. I also have a gearwrench inch torque wrench: http://www.amazon.com/dp/B000NI9442/?tag=atomicindus08-20 the 3/8 gearwrench goes down to 5lbft and is pretty accurate down low.

 

[Charles (in GA)]

ANSI and comparable EU and Australian standards say that a torque wrench is only certified accurate from 100% of its scale, down to 20% of its scale. If its a 100 lb/ft max tool, then the low end is at 20 lb/ft. If it is 150 lb/ft max such as yours, the minimum is 30 lb/ft. Even if the tool has markings below that, it is considered unusable below that.

Contrary to what others say, if a TW is calibrated it is certified to be accurate within the precentage specified by the manufacturer (usually 4%, sometimes as much as 6% and sometimes as little as 2%) of scale. Thus at 100 lb/ft setting, you might be more, or less, by a small amount and still be within the accuracy specified by the manufacturer. This is for the full range, 20% to 100%. The torque wrench is just as accurate at the lowest "legal" setting as it is at midrange, or top of scale, if properly calibrated and certified.

Anything made by Precision Instruments, CDI (a Snap On company), Sturtevant-Richmont, Sekonk, Norbar, Proto, or any one of several other old torque wrench companies, will do the job nicely.

Very easy to step up or down in drive sizes using adapters, everyone, including Craftsman makes them. Lots of arguments on using extensions (not offsets, but regular extensions) on torque wrenches. Fact is, it doesn't affect the torque. If you could not use extensions on a TW, you would not get much work done.
Charles

 

[Memory Leak]

ANSI and comparable EU and Australian standards say that a torque wrench is only certified accurate from 100% of its scale, down to 20% of its scale. If its a 100 lb/ft max tool, then the low end is at 20 lb/ft. If it is 150 lb/ft max such as yours, the minimum is 30 lb/ft. Even if the tool has markings below that, it is considered unusable below that.

Contrary to what others say, if a TW is calibrated it is certified to be accurate within the precentage specified by the manufacturer (usually 4%, sometimes as much as 6% and sometimes as little as 2%) of scale. Thus at 100 lb/ft setting, you might be more, or less, by a small amount and still be within the accuracy specified by the manufacturer. This is for the full range, 20% to 100%. The torque wrench is just as accurate at the lowest "legal" setting as it is at midrange, or top of scale, if properly calibrated and certified.

Anything made by Precision Instruments, CDI (a Snap On company), Sturtevant-Richmont, Sekonk, Norbar, Proto, or any one of several other old torque wrench companies, will do the job nicely.

Very easy to step up or down in drive sizes using adapters, everyone, including Craftsman makes them. Lots of arguments on using extensions (not offsets, but regular extensions) on torque wrenches. Fact is, it doesn't affect the torque. If you could not use extensions on a TW, you would not get much work done.
Charles

Thank you for your post, its very informative. One last question I had was, does it matter if the extension is in the size of the TW or the adapter? Sensible thing to do is to buy it in the wrench's size and add the adapter on top of the extension, but I still wanted to check.

 

[darwyn]

Thank you for your post, its very informative. One last question I had was, does it matter if the extension is in the size of the TW or the adapter? Sensible thing to do is to buy it in the wrench's size and add the adapter on top of the extension, but I still wanted to check.

Torque is a tendency of a force to rotate an object. In this case the object is a bolt. As long as your extensions are parallel to the bolt, torque is not effected. Now if you put a crow's foot on the end of your extension, you've got some math to do.

One thing that did not get mentioned here is that you have to be careful with torque values, particularly on oil pan bolts. On a motorcycle forum I used to hang out on new guys stripped oil pan bolts semi-regularly using the factory torque specs.

Torque specs are given for a dry bolt, in an oil pan that is not going to happen unless you are putting on a brand new oil pan. Lubricants change torque specs dramatically, in the case of oil you would cut the torque spec in half. My point is that if you put anything on the bolt, oil, thread locker, etc. you have to take that into account.

 

[Memory Leak]

Torque is a tendency of a force to rotate an object. In this case the object is a bolt. As long as your extensions are parallel to the bolt, torque is not effected. Now if you put a crow's foot on the end of your extension, you've got some math to do.

One thing that did not get mentioned here is that you have to be careful with torque values, particularly on oil pan bolts. On a motorcycle forum I used to hang out on new guys stripped oil pan bolts semi-regularly using the factory torque specs.

Torque specs are given for a dry bolt, in an oil pan that is not going to happen unless you are putting on a brand new oil pan. Lubricants change torque specs dramatically, in the case of oil you would cut the torque spec in half. My point is that if you put anything on the bolt, oil, thread locker, etc. you have to take that into account.

Thanks, I have read a lot of forum threads about my particular car and a lot of people use these torque values with no issues. The spec says 18NM, one person who tightened by hand found out he actually tightened it to 35NM after checking with the torque wrench and even then he didn't stripped the bolt.

I'm actually more afraid over tightening by hand than by the torque wrench as 18NM is not much.

 

[nicksnothereman]

Hi again,

Thanks a lot for very helpful responses. I had no idea about not using a torque wrench to loosening lug nuts. I did this several times I guess I may have thrown the calibration off. How can I check to see if the calibration is not off?

I am going to get a Tekton inch/lb torque wrench as well. Looking to get this one : http://www.amazon.com/dp/B00C5ZL2EG/?tag=atomicindus08-20.

That being said, all of my hex sockets are 3/8. Is it going to be a problem to get an adapter? Furthermore, if I need an extension for the wrench, should the extension be in the wrench's size or the hex socket's size? i.e. the wrench is 1/4 inch and the hex socket is 3/8. I will get an adapter to go from 1/4 to 3/8. So should the extension be 1/4 or 3/8? Does having both an adapter and an extension impact the torque wrench in a bad way? I couldn't find a good inch/lb wrench that has a low range. I am going to need 10NM and 18NM. The lowest I could find was 20-200. Also, if there is a better brand you can recommend, feel free to do so.

I don't want to go cheap on this stuff. As for those of you saying hang tighten the drain plugs, I don't want to really argue but if the manufacturer said 18NM specifically, why go against it? Especially in a car like this. You never know what might happen in the future in a warranty claim I wouldn't want to be blamed for not following instructions.

Thanks again for your help.

Your calibration probably isn't off (any worse than from factory) it's usually something that worsens with age of the tool if you do it and continue to do it and don't store it right (see below).

1/4 accuracy tolerances are worse than 3/8 and 1/2. My suggestion is that if you actually need a torque wrench NOW you get a stop gap. Not as good as a truck brand, better than most store brands. Husky (home depot) has decent ones as well as the kobalt (taiwan) ones. I personally use a kobalt torque wrench and it's is awesome both with accuracy and ease of twist (has a lift up mechanism).

OR You could just get a beam torque wrench for under 20 bucks and not worry about the calibration (because there is none). These are what I use for lower torque values. Not fancy but get the job done every single time and don't have to worry about calibration failure. There are more expensive ones but they all will do the same thing. I've got a craftsman and I really use it, no fooling!

Off load the torque after using a torque wrench that is not beam to the lowest registered value to maintain calibration.

As far as throwing off the value...if the head of the torque wrench is over the bolt it won't throw off the value at all, if you use a swivel or u-joint it will. That having been said, if you can't get at it any way else with a torque wrench...it's better than nothing...until you CAN get at it properly with a torque wrench.

 

[darwyn]

I'm actually more afraid over tightening by hand than by the torque wrench as 18NM is not much.

I'll bet your friend used a 3/8 drive ratchet. If you are nervous about it I would use 1/4 drive ratchet, that should put you in the range you are looking for.

 

[trxrx7]

if you've been wrenching for a while you kinda know what 15,30, 60, 90 etc. feels like. so you wouldn't really use a tw on a drain plug. where i do use a tw is on anything internal on an engine, ******, clutch, drivetrain, bearings, lug nuts and stuff like that, it kinda helps if you have a feel for it especially if you get paid by the units then it will save you alot of time. but if you are new to it, and you don't do it for a living then there is nothing wrong with using a tw on a drain plug or anything else till you are comfortable without it, and also the parts are designed to with stand a little more torque than stated so if you over torqued something its not the end of the world(unless you really over torqued )

 

[luv2diy]

Thanks, I have read a lot of forum threads about my particular car and a lot of people use these torque values with no issues. The spec says 18NM, one person who tightened by hand found out he actually tightened it to 35NM after checking with the torque wrench and even then he didn't stripped the bolt.

I'm actually more afraid over tightening by hand than by the torque wrench as 18NM is not much.

It's cool you are learning how to work on your own car! Tools are a great investment. I have a 3/8" (used) snap-on TW from 5 ft-lb to like 80 or something, and 1/2" (New) Armstrong TW for my wheels. Both purchased from flea Bay.

You really can't mess up, tighten you oil plug by hand, set your TW to it's setting.. hear a click and your done!

 

[Denwad]

Thanks, I have read a lot of forum threads about my particular car and a lot of people use these torque values with no issues. The spec says 18NM, one person who tightened by hand found out he actually tightened it to 35NM after checking with the torque wrench and even then he didn't stripped the bolt.

I'm actually more afraid over tightening by hand than by the torque wrench as 18NM is not much.

Memory Leak, what kind of M3 do you have?

I used a 1/2 ratchet and torqued mine so tight it snapped the head off the drain plug, the threads in the pan were unaffected.

good thing considering the oil pan is a total PITA to replace on most BMWs

 

[Memory Leak]

Memory Leak, what kind of M3 do you have?

I used a 1/2 ratchet and torqued mine so tight it snapped the head off the drain plug, the threads in the pan were unaffected.

good thing considering the oil pan is a total PITA to replace on most BMWs

I have a 2011 E90 M3.

I'm going to be extremely careful not to over tighten the plugs, all these horror stories are scaring me.

 

[Memory Leak]

Is it a bad idea to use a beam torque wrench for drain plugs?

 

[AMCguy]

Not a bad idea at all. A beam type is simply a different (simpler) and in my opinion superior design.

The only disadvantage I can think of when using a beam type is, you have to position your eyes directly over the wrench to accurately read it. You also have to hold the specified torque value for a few seconds. This can be somewhat fatiguing on a large engine with multiple head bolts or main cap bolts that require well over 100 ft/lbs. It might also be impossible to use a beam type in an out of the way location in an engine bay.

For some of the work I do, I prefer to use my beam torque wrenches. It's a slower more pain staking process but I'm more interested in accuracy not speed.

I own both beam type and click type torque wrenches in both ft/lbs and in/lbs.

 

[Memory Leak]

One other question I have is, I want to buy a breaker bar to loosen lug nuts (for future) as well as oil drain plugs since I know better than using a torque wrench to do this That being said, I don't know whether or not I should go with a very long one or a medium size one. I understand that longer it is the easier it is to break something loose. Is 20 inches good enough?

In terms of the size, should I go with 1/2 inch or 3/8 inch? I guess the bigger the more force you can apply, but at the same time wouldnt want to damage something as small as the drain plugs.

By the way, this is the plug I will be working with : http://www.eagleday.com/bmw-m-serie...medium=adwords&id=19600381160&utm_content=pla

 

[the.wong.kid]

I would recommend a 1/2 breaker bar for the lugnuts. Since bmws use torx bolts for the drain plugs and not a regular bolt, u cant use long leverage wrenches/spanners I would recommend buying a long reach 3/8 rachet

i deal with japanese cars all day and majority either use a 14mm drain bolt(nissan/infiniti/toyota/lexus etc) or a 17mm drain bolt (honda/acura) and this snap-on long reach double box wrench works great for my application well worth my investment. also works great in other applications like brakes when a swivel and gun can get into areas
http://store.snapon.com/Box-0-176-O...x-0-176-Offset-14-17-mm-12-Point-P633887.aspx
Sent from my SCH-I545 using Tapatalk

 

[Memory Leak]

I would recommend a 1/2 breaker bar for the lugnuts. Since bmws use torx bolts for the drain plugs and not a regular bolt, u cant use long leverage wrenches/spanners I would recommend buying a long reach 3/8 rachet

i deal with japanese cars all day and majority either use a 14mm drain bolt(nissan/infiniti/toyota/lexus etc) or a 17mm drain bolt (honda/acura) and this snap-on long reach double box wrench works great for my application well worth my investment. also works great in other applications like brakes when a swivel and gun can get into areas
http://store.snapon.com/Box-0-176-O...x-0-176-Offset-14-17-mm-12-Point-P633887.aspx
Sent from my SCH-I545 using Tapatalk

What would happen if i used a 3/8 adapter to the 1/2 breaker bar to loosen the drain plugs?

 

[the.wong.kid]

What would happen if i used a 3/8 adapter to the 1/2 breaker bar to loosen the drain plugs?

Nothing, u can do that way if u like.

Sent from my SCH-I545 using Tapatalk

 

[kenburkholz]

If you are trying to find the torque a fastener was tightened to, you can't find that by measuring the torque required to loosen it, the initial torque to get the fastener loose would be far greater than the actual torque it was tightened to, Welcome aboard! Ken.

 

[uart]

Torque specs are given for a dry bolt, in an oil pan that is not going to happen unless you are putting on a brand new oil pan. Lubricants change torque specs dramatically, in the case of oil you would cut the torque spec in half.

I'm pretty sure that the torque specified in the service manual for an *oil* drain plug will have already taken that into account. I wouldn't recommend halving it.

 

[6-Speed]

You don't need a breaker bar to remove a drain plug torqued to 18 NM; a regular box end wrench will break it loose with a sharp whack of your palm. I would use a torque wrench calibrated in lb-in; I have a 3/8" in drive TW with a range between 25 to 250 lb-in that would be ideal.

 

[Memory Leak]

I bought the these two torque wrenches after much deliberation :

http://www.amazon.com/gp/product/B0032A60W2/?tag=atomicindus08-20

and

http://www.amazon.com/gp/product/B004VYUQI2/?tag=atomicindus08-20

In addition, I got :

http://www.amazon.com/gp/product/B00943SONE/?tag=atomicindus08-20
http://www.amazon.com/gp/product/B00943KFTA/?tag=atomicindus08-20
http://www.amazon.com/gp/product/B000NPT5JO/?tag=atomicindus08-20
http://www.amazon.com/gp/product/B000NPZ5S4/?tag=atomicindus08-20
http://www.amazon.com/gp/product/B000NPT5I0/?tag=atomicindus08-20